Standardised load-time histories- a contribution to durability issues under spectrum loading

It is well established that the fatigue performance of materials and structures may be very sensitive to the specifics of the loading encountered. Beside constant amplitude testing, therefore, tests with realistic load sequences are often required in order to assess any susceptibility to the specifics of variable amplitude loading and to demonstrate the inservice integrity for given materials and structures. For these purposes standardised loadtime histories (SLH's) have been developed for 30 years since it has been recognised that the use of SLH's a series of advantages practical applications. Starting with Gassner's block programme test, some features of standardised load-time histories available at present and their relevance for fatigue behaviour of materials and structures are reviewed.